With the advances in the nanotechnology, the demands of ability to build materials and products in nanometer scale, or even atomic precision are increased rapidly. Accordingly, various technologies of nanometer processing have been discussed and developed vigorously. Among those technologies that have been made public, the nanoimprint lithography (NIL) is a promising technology that possesses the potential advantages of low cost and high yield. The technology of nanoimprint lithography requires only a single imprinting step to repetitively transfer the same nanostructured pattern on a large area wafer substrate, which can be applied to nanometer electronics, optical components, high density storage devices, nanometer electromagnetic devices, biological apparatuses, transducers, nanometer electromechanical components, and so on.
However, although the nanoimprint lithography technology possesses the above-mentioned advantages and potentials, there're still few drawbacks required to be improved after the technology was published a few years ago. For instance, the alignment capability accompanied with the fabrication of multi layer components, the large scale molds for enhancing throughput, the high-density nanopatterning molds, mold sticking, polymer solidification, imprint temperature and pressure, the life of mold, and the making of the standards in determining the quality of the end products and the effectiveness of the products, are just some examples required to be dealt with. For these reasons, the technology of nanoimprint lithography is not practically commercialized yet, but is realized only in forms of laboratory prototypes or some research oriented machines. Among those issues, the improvement of the throughput is the most critical one. Therefore, how to perform an online real-time monitoring on the process parameters currently tuned manually to realize the automated processing and to enhance the throughput becomes the ultimate goal of commercializing the nanoimprint technology.
Moreover, in the entire nanoimprint process, the status of the resist being embossed by a mold and the timing to demold are the critical factors affecting the product quality. Please refer to Attachment 1, which is extracted from the paper published in the Institute of Physics Publishing by H. Schift et al. in 2001 depicting the defects caused by the poor processing parameters setting for defining the timings of imprinting and demolding in the nanoimprint process. If demolding too early, the quality of the nanopatterning structures and components will be degraded and the products will be unable to commercialize. If demolding too late, although the quality of the products may be improved, the production throughput will be severely reduced due to the overall prolonged imprint duration. Therefore, to maintain the accuracy of the products within nanometer scale and also raise the overall throughput of the imprint process, an online real-time monitoring must be performed for monitoring the status of the resist being embossed by a mold in order to obtain the real-time information of the status of the resist and achieve an automated processing control.
The primary object of the present invention is to provide a simple and accurate method and system capable of monitoring and recording the real-time status of the resist being embossed by a mold as timing references for demolding in a nanoimprint process, and therefore automating the nanoimprint process, improving the quality of the nanopatterning products and the raising the throughput of the nanoimprint process.